This is hardly the first entrant and pretty much every tv and blu-ray you buy moving forward will have similar capabilities to what Google has announced. Though perhaps with a different provider.
Yahoo actually has the most TV's out right now with similar interactivity using their widget platform. They're on Sony, Samsung, Vizio and LG tvs http://connectedtv.yahoo.com/
Samsung has their own platform running on their TVs and blu-ray players. Its an HTML engine and also supports a "Flash Lite" or Stagecraft. (and their tvs still run yahoo widgets as well) http://www.samsung.com/us/internetTV/
Vudu (recently bought by Wal-Mart) has an app platform being supported by many manufacturers as well its Lua based and on Toshiba, LG and Sanyo products. (this is outside of their on-demand video service)
Panasonic has "Viera Cast" which is actually a cloud based service I haven't really figured out yet
So besides these there's quite a few "Over The Top" boxes that provide similar functions such as
Roku
Popcorn Hour (about to launch their new Popbox in a bit)
Apple TV
Boxee
Anyway its fun to see Google hopping into the space we'll see how well they do.